I’m not yet sure what a precomp is, but it is not a layer, at least not in the timeline. When I right-click the arrow, it says the keyframe position, followed by various options for that individual keyframe.

What I ultimately want to do is lower how high the arrow raises to. That top-left keyframe, I would like to be a little lower. I don’t know how to move ~every~ keyframe lower, all I end up doing is making it briefly go up a bit lower, but then continue to where it always goes.